In case you were curious, here is what an alien sees before he/she/it goes to sleep.

NASA’s Curiosity Mars rover captured the above image on April 15, and it’s being described as the first sunset observed in color by the spacecraft.

The photos were taken last month, but they were just sent back to Earth last week.

While Mars may appear red, the sunset is actually blue, and the Jet Propulsion Laboratory explains why this is possible:

Dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colors in the mixed light coming from the sun to stay closer to sun’s part of the sky, compared to the wider scattering of yellow and red colors. The effect is most pronounced near sunset, when light from the sun passes through a longer path in the atmosphere than it does at mid-day.

Curiosity first landed on Mars’s Gale Crater in August 2012 with a mission of determining whether or not Mars is or ever was habitable by life forms.

Here’s an animated GIF of the sunset, which uses a series of photos takes over a period of about 6 minutes, 51 seconds. The sight apprently inspired the rover to recite some lines from T.S. Eliot’s “The Love Song of J. Alfred Prufrock” on its Twitter account.